Theoretical bounds are commonly used to assess the limitations of photonic design. Here we introduce a more active way use theoretical bounds, integrating them into part design process and identifying optimal system parameters that maximize efficiency limit itself. As an example, consider wide-field-of-view high-numerical-aperture metalenses, which can be for high-resolution imaging in microscopy endoscopy, but no existing has achieved high efficiency. By choosing aperture sizes bound,...

Transition-metal dichalcogenides in the 1T phase have been a subject of increasing interest, which is partly due to their fascinating physical properties and potential applications next generation electronic devices, including supercapacitors, electrocatalytic hydrogen evolution, phase-transition memories. The primary method for obtaining WS2 or MoS2 has using ion intercalation combination with solution-based exfoliation. resulting flakes are small size tend aggregate upon deposition,...

Abstract Numerical solutions of Maxwell’s equations are indispensable for nanophotonics and electromagnetics but constrained when it comes to large systems, especially multi-channel ones such as disordered media, aperiodic metasurfaces densely packed photonic circuits where the many inputs require large-scale simulations. Conventionally, before extracting quantities interest, first solved on every element a discretization basis set that contains much more information than is typically...

Contact engineering has been the central issue in context of high-performance field-effect transistors (FETs) made atomic thin transition metal dichalcogenides (TMDs). Conventional contacts on TMDs have top via a lithography process, forming top-bonded contact scheme with an appreciable barrier. To provide more efficient pathway for charge injection, end-bonded proposed, which covalent bonds are formed between and channel edges. Yet, little efforts to realize this configuration. Here, we...

One of the primary limitations previously reported two-dimensional (2D) photodetectors is a low frequency response (≪ 1 Hz) for sensitive devices with gain. Yet, little efforts have been devoted to improve temporal while maintaining high gain and responsivity. Here, we demonstrate 6.3 × 103 electrons per photon responsivity 2.6 A/W simultaneously exhibiting an ultrafast time 40–65 μs in hybrid photodetector that consists graphene-WS2-graphene junctions covered indium (In) adatoms atop. The...

This paper introduces the Precomputed Numerical Green Function (PNGF) method, a new approach for rapid inverse design of electromagnetic devices. The static components are incorporated into numerical function obtained from single fully parallelized precomputation step, reducing cost evaluating candidate designs during optimization to only being proportional size region under modification. When used with direct binary search algorithm, low-rank update technique is leveraged further decrease...

Computer-automated design and discovery have led to high-performance nanophotonic devices with diverse functionalities. However, massively multichannel systems such as metasurfaces controlling many incident angles photonic-circuit components coupling waveguide modes still present a challenge. Conventional methods require Min forward simulations adjoint simulations─2Min in total─to compute the objective function its gradient for involving response input channels. Here, we develop formalism...

The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in metal oxide semiconductor nanowires (NWs) have been investigated. experimental result surprisingly shows SnO2, TiO2, WO3, ZnO NWs reveal extraordinary common, which are over one to three orders of magnitude lower than theoretical expectation. surface depletion region (SDR)-controlled photoconductivity is proposed explain anomalous its power dependence. inherent difference between nanostructures...

The photoconduction (PC) efficiencies of various single-crystalline metal oxide semiconductor nanowires (NWs) have been investigated and compared based on the materials' inherent properties. defined PC efficiency (normalized gain) SnO2 NWs is over one to five orders magnitude higher than that its highly efficient counterparts such as ZnO, TiO2, WO3, GaN. property material allowed photoconductive gain an single-NW photodetector easily reach 8 × 108 at a low bias 3.0 V light intensity 0.05...

A striking prediction from the random matrix theory (RMT) in mesoscopic physics is existence of “open channels”: waves that use multipath interference to achieve perfect transmission across an opaque disordered medium even multiple-scattering regime. Realization such open channels requires a coherent control complete incident wavefront and has only been achieved for scalar two dimensions (2D) so far. Here, we utilize recently proposed “augmented partial factorization” full-wave simulation...

Computer-automated design and discovery have led to high-performance nanophotonic devices with diverse functionalities. However, massively multi-channel systems such as metasurfaces controlling many incident angles photonic-circuit components coupling waveguide modes still present a challenge. Conventional methods require $M_{\rm in}$ forward simulations adjoint -- $2M_{\rm in total compute the objective function its gradient for involving response input channels. By generalizing method...

A striking prediction from the random matrix theory in mesoscopic physics is existence of "open channels": waves that can use multipath interference to achieve perfect transmission across an opaque disordered medium even multiple-scattering regime. Realization such open channels requires a coherent control complete incident wavefront. To date, have only been demonstrated scalar two-dimensional (2D) structures, both experimentally and with numerical studies. Here, we utilize recently proposed...

Wavefront shaping can tailor multipath interference to control multiple scattering of waves in complex optical systems. However, full-wave simulations that capture are computationally demanding given the large system size and number input channels. Recently, an "augmented partial factorization" (APF) method was proposed significantly speed-up such simulations. In this tutorial, we illustrate how perform wavefront with APF using open-source frequency-domain electromagnetic solver MESTI. We...

Abstract Wavefront shaping can tailor multipath interference to control multiple scattering of waves in complex optical systems. However, full-wave simulations that capture are computationally demanding given the large system size and number input channels. Recently, an ‘augmented partial factorization’ (APF) method was proposed significantly speed-up such simulations. In this tutorial, we illustrate how perform wavefront with APF using open-source frequency-domain electromagnetic solver...

We identify optimal system parameters that maximize the upper limit of transmission efficiency and then perform inverse design to find high-NA wide-field-of-view metalenses with a record-high (98% transmission, 92% Strehl ratio, NA = 0.9).

Abstract Multi-channel optical systems such as disordered media, metasurfaces, multi-mode fibers, and photonic circuits are of both fundamental technological importance. However, their responses difficult to describe in the presence multiple scattering, strong coupling, multi-path interference. Accurate modeling requires many large-scale simulations associated with input states, which currently take enormous computing resources. We propose an approach where all solved jointly efficiently by...

We report on the first observation and study of coherent backscattering entangled photon pairs. show that after photons backscatter from a dynamic random medium, they remain correlated, exhibiting new mesoscopic phenomenon.

We describe full-wave single-shot computations for multi-source electromagnetic problems in both 2D and 3D using the "augmented partial factorization" method. This versatile approach bypasses unnecessary avoids repetitions to achieve many orders of magnitude speed-up compared conventional methods.

Topology optimization of nonlocal metasurfaces requires the objective-function gradient considering all angles interest. We generalize recent "augmented partial factorization" method to compute such efficiently and inverse design a broad-angle metasurface beam splitter.

We describe full-wave single-shot computations for multi-source electromagnetic problems in both 2D and 3D using the "augmented partial factorization" method. This versatile approach bypasses unnecessary avoids repetitions to achieve many orders of magnitude speed-up compared conventional methods.